Dental plugger



in. E. COULSON. DENTAL PLUGGER.

(No Model.)

Patented July 21,1891.

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IINrTED STATES PATENT OFFICE.

DAVID E. COULSON, OF GALESBURG, ILLINOIS.

DENTAL PLUGGER.

SPECIFICATION forming part of Letters Patent No. 456,477, dated July 21, 1891.

Application filed May 23, 1890. Serial No. 352.855. (No model.)

To all whom it may concern:

Be it known that I, DAVID E. COULSON, of JraIeSburg, countyof Knox,ai1d State of Illi` nois, have invented certain new and useful Improvements in Dental Pluggers, of which the following is a specification, reference being had to the accompanying drawings My invention relates to improvements by which a thrust and back blow can be struck upon an instrument.

The object of my invention is to produce a plugger which is adapted to be easily manpulated by an operator and to have the impact `ot its hammer regulated with facility, and one which, by reason of the directness of action ot' its Working parts, will not get out of order.

`Another object is to provide means for securing the plugger readily to a flexible cable or the like, and also for preventing' Vpressure that would impede its motion upon the end of the cable when the plugger is fastened to it.

In the accompanyingdrawings, Figure l. is a central longitudinal section of my handpiece, showing all the parts of the same. Fig. 2 is a view ot a part of the hand-piece detached. Fig. 3 is a view partly in section of the shaft-coupling device detached. Fig. et is a view of the hammer and eccentric detached. Fig. 5 is a view of the shaft connection detached. Figs. (j and 7 are longitudinal sections through the parts adapted to fasten the plugger to a revolving shaft, showing the shaft and its uniting parts in elevation.

Referring tothe letters on the drawings, A indicates a hollow handpiece. It is roughened at its lower end to facilitate holding it and at the other end is internally screwthreaded to receive the screw-threads of the bushing l5. An annular flange (l is located in the middle ot the bushing to form a cap for the hand-piece A and abase forthe collar D,which is rotatably secured to the upper part of the bushing by the annular 11 ut E, that lis adapted to screw upon theuppercnd oi' the bushing.

Passing upward through the handpicce is a rod F, which terminates at the lower end of the hand-piece in an ordinary tool-holder. Within the hand-piece upon this rod are provided two lugs G, which take into the slots or kerfs II .in the lower end ot' the bushing to limitthe longitudinal motion ot the rod. Above the lugs upon the rod is provided a shoulder I, which when the parts are in place lits neatly into the upper end of the bushing B and is designed to receive the blows ot' the hammer R.

The outside of the collar D is screw-threaded to enter the internalIysereW-threaded end of the sleeve J. This sleeve is provided on one side with a longitudinal slot K and o'n the other with an oblong opening L. It is also provided at each end with external screwthreads. Upon its lower end is carried an internally-screw-threaded collar M, provided with an annular flange N at its lower end. Upon the other end is carried the internallyscrew-threaded cap O. The rod F extends entirely through the sleeve and terminates in a screwthreaded end that carries by this means an internally-scre\vthreaded cap Q.

Longitudin ally movable upon the rod F is the hammer R, which is confined within the sleeve between fixed limits by the shoulder I on the rod F and the cap Q upon the end of the rod, against one of which it strikes a blow in each reciprocation. The hammer is provided upon one side with a fiat longitudinal incision S and in the middle with a transverse slot T. Surrounding the sleeve between the llange N of the collar M and the cap O is carried the cover V, which, with the sleeve J and parts connected therewith, constitutes the case. The cover is provided upon one side with the set-screw lV, that is fixed to it and passes through the slot in the sleeve, whereby the sleeve may move longitudinally within the cover, but may not rotate. In otherwords, the sleeve .l and the cover V are securely united together, but are adapted to be moved longitudinally within certain limits, the one within the other. Upon the opposite side the cover V is provided with an internally-screwthreaded hollow projection X, that carries the externally-serewthreaded bushing Y, within which rotates the shaft Z, which carries upon its inner end. the eccentric A', provided with a pin U, and upon its other end by means of screw-threads or other suitable device the fiat-sided head l3, to which a revolving shaft is adapted to be coupled. The eccentric A is thus kept in constant close operative relations with the hammer R, and by reason of IOO the flat head of the eccentric being close to the fiat side of the ham mer-head made by the longitudinal incision S prevents the hammer from turning. Thus the hammer R and the cover V are irrevolubly iXed to each other. Behind this head, upon the outer end of the bushing, is screwed the collar C', which is provided at its outer end with opposite angular slots D' of the kind that are used in the Well-known bayonet-joint.

E indicates a cylinder provided with internally-projecting lugs F', adapted to enter the angular slots of the collar C.

G' indicates a sliding collar provided with lugs H', which, when the cylinder has been attached tothe collar C' by means of the lugs, slip into the open end of the angular slots and lock the cylinder to the collar.

I' indicates transverse slots on each side of the sliding collar, and J' indicates longitudinal slots in opposite sides of the cylinder. The outer end of the cylinder is provided with an internal annular projection L', upon which at one end is seated the spring M', that presses at its other end against the internally-sliding collar and projects it against the internallyprojecting lugs F.

N indicates a bushing adapted to be screwed into the outer end of the cylinder, which is screw-threaded to receive it, and provided at its outer end with external screwthreads, which are adapted to be fastened to the case of an ordinary flexible cable.

P' indicates a sliding collar which surrounds the cylinder E. It is provided on opposite sides with set-screws Q', that pass through the longitudinal slots in the cylinder and enter the transverse slots in the internally-sliding collar. By this means a longitudinal movement of the sleeve maybe communicated to the internally-sliding collar, while the latter is at the same time susceptible of being partially rotated by means of the transverse slots independently of the sliding sleeve.

`In order to fasten the cylinder audits parts to the collar C', the sliding sleeve is pressed downward, so as to permit the lugs F' to enter the angular slots in the collar C'. Then by turning the cylinder slightly the lugs enter the recesses in the angular slots. As soon as the flexible shaft is caused to revolve the internally-sliding collar moves around until the lugs upon it enter the open ends of the angular slots, when the spring presses the sliding collar forward and locks the cylinder to the collar C. A shaft R' is loosely carried in the central part of the cylinder and is adapted to communicate motion from the ileXible shaft to the shaft Z. The inner end of the shaft R' is provided with a longitudinally-movable head S,which is provided with a pair of lugs T', adapted to fit over the nat-sided head B'. A fixed head U is carried upon the end of the shaft R' between the lugs T.

V indicates a coiled spring surrounding the shaft R and seated upon projections on the shaft and the inside of the movable head S', so as to keep-the latter yieldingly pressed against the fixed head U. When the cylinder is united to the collar C' in the manner above described, if the `Hat-sided head B' should project a greater distance into the interior of the cylinder than is provided for, instead of binding against the end of the shaft R', and thereby producing friction, the yielding head S would be pressed backward; but communication from the shaft R' to the shaft Z would be perfectly established. Of course any sort of instrument might be united to 'this coupling in the manner described, and

of the arrangement just explained by means be dispensed absolute precision of joints may with, which is very desirable.

The operation of my machine will be clearly understood from the following description: Suppose that the shaft Z is caused to rotate by means of a flexible cable driven by any suitable means. The eccentric A' will be caused to rotate and will drive the hammer R backward and forward through the sleeve J. It

will `be observed that the hammer is conlined in the length of its travel by the eccentric, so that it cannot escape from the operation of the shaft. If the cover V is moved down toward the hand-piece A by unscrewing the collar M and screwing down the cap O, the lower end of thehammer will be caused to strike the shoulder l each time it reciprocates within the sleeve J. By this means the thrust blow is given through the rod F to the tool. Byv the reverse movement of the collar M and the cap O the hammer is caused to strike the cap Q upon the rod F, in which position the back blow is communicated through the rod F to the tool. It will be observed that by this means of adjustment the force of the blow can be regulated from the lightest stroke to the heaviest of which the machine is capable.

It will be understood that the relations of the parts are such that when the hammer is set to strike upon one end it does not strike upon the other, so that a blow in only one direction is communicated by the operation of the machine.

I do not confine myself to all the details of construction specified, because they may be varied in many ways without departing from the scope of my invention. I refer specially to the mechanism for causing the reciprocation of the hammer, and also that for adjusting the position of the hammer with respect to the sleeve within which it reciprocates and the rod. The adjustability of the hammer by some means is in this regard the important thing.

-What I claim is l. In a dental plugger, the combination, with a tool-carrying rod F and its case, of a hammer surrounding the rod and adapted to reciprocate between fixed limits thereoma cover V, longitudinally adjustable upon the case, an eccentric A', through which reciprocatory motion may be imparted to the ham- ICO IOS

IIO

mer, and means for fixing the adjustment of the cover, whereby the hammer maybe made to strike against one or the other ot its fixed limits, as desired, to impart a thrust or back blow to the rod, substantially as set forth.

2. The combination, with the rod F and the hammer R, adapted to reciprocate between fixed limits thereon, of the hand-piece A, surrounding the lower end of the rod F, the bushing 3, secured thereto, a collar D, rotatably carried upon the bushing, the slotted sleeve J, secured to the rotatable collar, the fianged collar M and the cap O, adj ustably xed thereto at opposite ends,and the eoverV,ad justable by means ot the collar M and the eap O upon the sleeve J and adapted to carry at right angles to it the eccentric A', through which reciproeatory motion may be imparted to the hammer, all substantially as and for the purpose specified.

3. In a dental plugger, the combination, with the reciprocatory hammer R, provided with the longitudinal incision S and the transverse slot T, of a cover V, irrevolubly fixed to the hammer and provided with the screw-threaded hollow projection X, the screwthreaded bushing Y, adapted to be secured thereto, the shaft Z, and the eccentric A', oar ried thereon, whereby reeiprocatory motion may be imparted to the hammer, substantially as set forth.

` jecting lugs F', adapted to enter the angular slots of the collar C', and the spring-actuated sliding eollar G', inclosed within fixed limits within the cylinderE and provided with lugs H, and the sliding collar P', fixed around the cylind erE', butlongitudinally movable thereon and provided with set-screws Q', that enter the transverse slots l' in the collar G', whereby the collar G may be moved lon- `eitudinally and at the same time maintain its revolubility independent thereof, substantially as set forth. Y

In testimony of all which l have hereunto subscribed my name.

DAVID E. COULSON. Witnesses:

FRANZ E. MELBURG, T. L. BICGIRR. 

